Apparatus for sterilizing cans



Feb. 9, 1960 R. w.'PLATT APPARATUS FOR STERILIZING CANS Filed May 8, 1957 INVENTOR. FOM zu p f BY I l l, a!

United States Patent O 2,923,985 APPARATUS FOR STERILIZING CANS Robert W. Platt, Skokie, Ill., assignor to National Dairy Products Corporation, a corporation of Delaware Application May 8, 1957, Serial No. 657,964

6 Claims. (Cl. 21-80) The present invention relates generally to a new and improvedmethod and apparatus for sterilizing magnetizable metallic articles. The invention relates more particularly to a method and apparatus for sterilizing mag- K netizable metallic cans and to a conveyor on the sterilizer apparatus for conveying cans through the sterilizer apparats.

The packaging of perishable comestibles in cans is a relatively inexpensive and usual method of commercially packaging such articles. It is the usual practice in the canning industry to deliver a can to a packaging plant with one end open and after a comestible is placed in the can, an end is placed on the open end of the can and the can is then sealed. Before a perishable comestible is placed in a can, however, the can is usually sterilized to prevent spoilage of the comestible.

Cans may be sterilized by immersing them in boiling water or by spraying them with steam. However, in some instances, the product which is to be packaged may be adversely affected by contact with the metallic walls of the can and in such cases the can is generally coated on the inside with a coating such as shellac, varnish, lacquer, plastic, etc. so that the contents of the can do not come into actual contact with the metal of the can. Such coatings may be affected by steam or boiling water and it may, therefore, be necessary to sterilize such a coated can with a solution which has sterilizing properties at lower temperatures. An example of such a solution -s water containing chlorine.

A canV may be sterilized by conveying it through a confined zone wherein the sterilizing solution is contacted with the can. One method that has been used for conveying a can along an assembly line, is to place the can upright on a moving conveyor belt. Such a method, however, is not generally suitable to use in sterilizing cans since in the sterilization process steam or other sterilizing medium tends to remain within the uprightcontainer. It is, therefore, preferred that a can be inverted, that is turned upside down so that the opening of the can is down, and conveyed in such inverted position through a sterilization zone wherein steam or other sterilizing medium may be sprayed upwardly into the can.

A can may be conveyed through a sterilizer, in the inverted position with the opening facing downwardly, on a perforated conveyor belt. The sterilizing liquid may then be directed upwardly through the perforations into the interior of the can. However, a disadvantage of such a system is that the lip of the open end of the can must rest on the perforated conveyor belt which may prevent effective sterilization of the lip portion of the can.

A can may also be conveyed in the inverted position by grasping it with mechanical jaws of one type or another and moving the jaws and can in unison. Such a system, however, is generally very complex since it usually requires complicated timing mechanisms for grasping and releasing the cans at the proper moment. The use of mechanical jaws is also generally unsatisfactory when sterilizing cans of various sizes ,since considerable adjustment of the mechanical jaws and timing mechanism is frequently necessary to accommodate these various sized cans. Further, the exteriors of cans are often painted or otherwise covered with a coating and any mechanical grasping of the cans may mar or deface the exterior coating.

It is, therefore, the principal object of the present invention to provide an improved method and apparatus for sterilizing cans. lt is another object of the invention to provide a novel and relatively simple method and apparatus for sterilizingmagnetizable metallic cans having an open end, with the open end facing downwardly so that a sterilizing medium may be sprayed upwardly into the cans. Another object of the invention is to provide an apparatus which will sterilize a large number of cans per unit time and which is readily adjustable to accommodate different size cans. A further object of the invention is to provide a novel and relatively simple conveyor on the sterilizer apparatus for conveying cans through the sterilizer apparatus.

Other objects and advantages of the invention will become apparent by reference to the following description and the accompanying drawings. i

In the drawings:

Figure l is a side elevational view partly in section of can sterilizing apparatus embodying various of the features of this invention; and.

Figure 2 is a sectional view taken along line 2 2 of Figure 1.

The method of the invention for sterilizing an open end magnetizable metallic can generally includes positioning the can so that the open end is facing downwardly and while in such position contacting the uppermost end of the can with the underside of a moving conveyor and maintaining the can in contact therewith and in fixed relative position thereto only by magnetic force. The can is then guided on the moving conveyor through a sterilization zone wherein the interior of the can is sprayed with a sterilizing liquid. After the sterilizing step, the can is guided through a washing zone wherein the interior of the can is sprayed with a washing liquid. The can is maintained in its inverted position on the moving conveyor for a sufficient length of time after leaving the washing zone to permit substantially all of the washing liquid to drain from the interior of the can after which the can is removed from contact with the conveyor and inverted to a position with the open end facing upwardly.

It has been found that good results are obtained in sterilizing cans when the interiors o-f the cans are first sprayed with warm water containing an active sterilizing agent, for example chlorine, and after this initial spraying operation, the cans are subsequently sprayed with warm water to remove the sterilizing agent therefrom.

Apparatus which may be employed for carrying out the method in accordance with various of the features of the invention is shown in the drawings and is described in the following paragraphs. While the machine shown is specifically adapted for the sterilizing of cans, it will be apparent that the method and apparatus of the invention may be used for sterilizing other magnetizable objects with equal facility.

The sterilizer 3 shown in the drawing includes a conveyor or feed means 5 at its forward end for conveying cans (not shown) in the upright position to an inverter 7. The cans to beconveyed may be any magnetizable metallic container such as those usually used for packaging foods. The cans are of the type having an opening at one end and the cans are placed or fed into the conveyor means 5 with the opening facing upwardly. The inverter causes the cans to rotate about a horizontal axis so that'the opening faces downwardly. The cans are continuously pushed through the .sterilizer 3 into a .washing zone or section y15.

arel being pushed netic force provided by an elongated magnet 11 which is adjacent to the upper surface of the lower run of the Ymoving conveyor belt 13. As the lower run of the conveyor belt 13 moves away from the inverter 7 the cans which are held incontact with the belt 13 are introduced to a sterilizing zone or section 12. In the sterilizing section 12, the cans are contacted with a spray of a suitable `sterilizing solution. In one commercial embodiment of the -invention the cans are sprayed with a warm solution `of water and chlorine. The cans, after Ibeing sprayed by the sterilizing solutionin the sterilizing section 12 of 1 .the sterilizer 3, lare continuously lmoved vthrough the .In the washing section 15 the cans are sprayed with sterile warm water. After the washing operation the cansare continuously moved from the washing section 15 through a draining section 16 wherein the cans .are allowed lto drain so that substantially all of the water drains from the cans while they are in positionwith the opening facing downwardly. As the cans exit from the draining zone 16 of :the sterilizer3 they are placed `in an inverter 17. `This in- ,verter 17 is similar to the inverter 7 at theinlet to the sterilizing section 12. As cans are -pushed through 'the .inverter 17 by subsequent cans being delivered to the inverter 17, the cans are turned 180 about a horizontal axis to anupright position and delivered to. a take-olf' Y conveyor 19. The Atake-off conveyorv19 thereupon may .convey the upright cans ,to a lling mechanism wherein ythe cans areilled with a comestible product.

Referring now more particularly to the drawings, the specific machine 3 illustrated embodies'various of lthefeatures of lthe invention, and as hasfbeen pointed out, it `is `particularly adapted to the-sterilization of cans. The .illustrated machine 3 includes a frame. 21 lof fabricated construction having a series ofsuitable support legs, and longitudinal' members which -are v,suitably connected together. The frame 21 supports 'various of themembers of the machine.

At one end of the `frame Zithere' is provided the con- -veyorgmeans 5, which may be of conventional design, for supplying the cans to the inverter 7,. `The conveyor means 5 shown inthe drawings includes a generally flat table platform 2'7 with a pair of horizontal spaced guide rods 23 above the platform. -These guide rods 23 are secured to the main frame 21 by vertical supports 25. Only one of the pair of guide rods 23 is shown with the other being positioned on the other side ofthe path of the cans. Thesehorizontal guide rods 23 -are arranged parallel to each other and are positioned and designed to prevent the upright cans from tipping from side to side and falling oif of the conveyor means 5. The cans-are' placed by hand or otherwise on the conveyor means 5 in a position with the opening up. The cans are then moved along the platform 27 between-the horizontal guide rods 2.3 into the inverter' 7 by a pair kof endlessy driving belts 29 which are mounted on the conveyor means 5 and are positioned to center the cans along the longitudinal center of the conveyor means -5 so that the cans may be properly introduced to the inverter 7. Only one of the pair of driving belts 29 is' shown in Fig. l; however, the other driving belt is positioned on the conveyor 5 on the opposite side of the path of the cans. Each of the endless driving belts 29 are drivingly mounted for rotation on a pair of driven rollers 31 and the rollers 31 arein turnrnountedgonvertical shafts 33. Power is suppliedin `theiusual manner to gone of :the rollers 31 v 4 is drivingly connected by way of pulley belt 39 and gear chain (not shown).

The inverter 7 may be of conventional design and is supported on the frame structure 21. The inverter 7 illustrated in the drawings is of generally cylindrical outline with the axis of the cylinder horizontal. The in` verter 7 is fabricated of a plurality of curved guide rails which guide the cans .to yturn through a 180 angle as the cans are pushed through the inverter 7. The cans are thereby inverted and positioned with the bottoms up and the open end down. v

As the cans near the exit end of the ,inverter 7, they move below theforward end of the conveyor means 9. The conveyor means 9 includes the conveyor belt 13 which is mounted upon .a pair of rollers, one roller 4S at the inlet or forward end of the sterilizer section 12 and the other roller 47 at the outlet or rearward end of the draining section 16. These rollers are rotatably :mounted on the frame 21. As may be seen .in Fig. l, the roller 45 vis positioned partially within the rearward or exit of the inverter? and some ofthe guide rails 35 ,extend beneath the roller 45. This feature of having the conveyork means 9 extending vinto the inverter 7 ypermits Vthe cans Inear `the outlet of the inverter 7 to be drawn against the underside of the moving conveyor belt 13 as the `cans leave the inverter 7. v 1 The `roller 47 at the outlet end of the draining section 16 is drivinglyconnectel lto a suitable source of power -cans Ythrough the st erilizing section :1 2, washing section 15 and draining section y16.

In Vorder to maintain the .proper tightness of the belt 11, a belt ltightener 46 is provided. Any suitable'belttightenermay.be used. The beltl tightener illustrated includes a frame `44 which is mounted =on the main `frame 21. Theframe 44 supports three rotatably mountedrollers, 46a', 461) and46c. The upper run of lthe-.conveyor vbelt 11 passes under the first roller46a, overthe middle roller 4,6b.and underthethird roller 46c. The middle roller 46b yis vertically adjustable, with its shaft 48 adjustably secured in a vertical slot S0 yinthe frame 44. As the middle `roller y46b lis moved upward, Lthe beltr 13 tightened and ,converselyas the middle roller 46 b is moved `downward the `belt is loosened. t .n

The cans with vtheir bottoms contacted by the lower run of the conveyor belt 13 are moved into the sterilization section 12 of the sterilizer 3. WhenY the cans leave the inverter 7 there is n o longer any support. given to the cansby the inverter 7; however, the cans are maintained in contact with the lower run of the conveyor belt 13 by the magnetic force set up by the elongated magnet 11.

This magnet 11 is of suilicient size and strength to provide a suciently. strong magnetic force to ymaintain the cans in Contact withv the conveyor belt 13. As `clearlyvshown in Figure 42, the ylower surface of the magnet 11 is adjacent tothe topside of the vlower runof the vbelt 13 so that the -xnagnetic force *of `the magnetv 11fis efficiently utilized.

The magnet 11 may be of the permanent ytype or it maybe an electromagnet. The elongated magnet 11,

vhowever,must provide sufficient magnetic force along its-entirelengthso that cans lare,retained against the conveyor'belt 13 at all ltimes as they are moved ythroughthe 2sterilization section 12 as well as throughvthe washing section 15 and draining section 16. As the causare being transported vthroughthe `sterilizing section 12 and washing section `15, the varioussprays of liquidinto the. cans tend to ldislodge the cans from their position on the conveYOl' belt 13. Therefore, the magnetic iield provided by the magnet `11 should be suiciently strong so that the cans are notY dislodged from the conveyor belt 13 atany time that .the cans are passing through these-sections- .Thc v-.sterilaatiqn section .12 `0f the sterilizer 43 includes ,a V,tank'57,having .a bottom-sloping to an outlet. The ytank 57 is relatively long and deep and has a relatively small width. The washing and draining sections, and 16 respectively, include a similar tank 58 which also has a bottom sloping to an outlet. are positioned adjacent to each other with their tops in the same plane and each of them is suitably supported on the frame 21. Instead of using two separate tanks, one tank may be used with a partition member therein which separates the tank into two sections. Such a tank construction will be obvious as the description of the apparatus progresses.

The tanks 57 and 58 have an elongated opening 60 extending longitudinally of the tops thereof. This opening also extends part way down the ends of the tanks. The transverse dimension of the elongated opening 60 is slightly wider than theV outside diameter of a can which is to be sterilized in the apparatus so that the can may be accommodated in the opening. As can be seen in Fig. 2, the top of each of the tanks includes inwardly extending ange portions61.

As is shown in Fig. 2, the conveyor belt 13 is wider than the` opening 60 and rests on the inwardly extending ange portions 61. The magnet is wider than the opening 60` and includes lower outwardly extending flange portions 49 secured to the inwardly facing flanges 61 of the tanks 57 and 58 by screws 62. Elongated spacer members 63 are provided between the flanges 61 and flange portions 49 to maintain the magnet 11 slightly above the inwardly extending flanges 61 so as to provide, a space for the conveyor belt 13. Suitable gaskets (not shown) may also be provided to insure a watertight fit so that water does not escape between the tanks and the magnet. The magnet 11 therefor bridges the opening 60 and closes the opening 60 at the tops of the tanks.

The conveyor belt 13 moves in the narrow space between the inwardly extending anges 61 and the magnet 11. The conveyor belt 13 may be a conventional type of belt; however, it should be of a non-magnetizable material so that it is not pulled up tightly against the magnet 11, thereby creating a drag on the belt as it is moved. Fabric belts or plastic belts are examples of suitable belts.

Since the magnet V11 is only across the opening 60 on the tops of the tanks, the extensions of the opening down the sides remain open and provide an inlet opening 65 into the tank 57, an opening 67 between the tanks 57 and 5S and an exit opening 69 from the tank 58. Each of these openings should have a vertical dimension greater than the outside length of a can to be sterilized on the apparatus and as previously indicated have a horizontal dimension greater than the outside diameter of a can to be sterilized. Openings are thereby provided into and out of the tanks 57 and 5S through which cans may be moved by the conveyor means 9.

In order that the tanks 57 and 58 may accommodate cans of various lengths, the tanks may be fabricated in two sections which are telescopically fitted together. In Fig. 2 the details of this type of construction are shown in reference to tank 57, it being understood that the tank 58 will be similarly arranged. Referring to Fig. 2, it may be seen that tank 57 has an upper section 57a and a lower section 57b, with the upper section telescopically fitting into the lower section. -In order to provide for relative adjustment of the upper section 57a as well as the conveyor means 9 which is on the upper section, screw VLllb, respectively, secured thereto, as by welding. The

The two tanks 57 and 58 l'Io .bers 61a and 61b in turn have suitable brackets 63a and v lower bracket 63b and a similar bracket 631.` (Fig. l), which is secured to a lower part of the frame Z1, hold an adjusting rod 61d so that the adjusting rod is rotatable but is not axially movable in the brackets 63b and 63e. The upper end of the adjusting rod 61d and the upper bracket 63a, however, are threaded and upon rotation of the adjusting rod 61d, the upper section of the tank 57a and the associated conveyor means 9 may be moved up or down. A handle 63d is provided on the lower end of each of the adjusting rods to facilitate turning of the rods. Instead of having each of the adjusting rods 61d independently adjustable, however, two or more of the adjusting rods may be connected together by a suitable connecting means (not illustrated). Such connecting means is operable to turn each of the adjusting rods through the same angle so that all the portions of the upper sections of the tanks 57 and 58 are movable up or down in unison, thereby maintaining the relative elevation of all the portions of the upper sections of the tanks and the conveyor means 9 the same.

A similar screw adjustment means 57C is illustrated near the outlet end of tank 58 and similar screw adjustment means (not illustrated) are provided on the opposite side of the apparatus to facilitate in raising or lowering the tanks 57 and 58, and the conveyor means 9. The inverters 7 and 17 are usually of the type which accommodate only one size of can and therefore when a can of a different size is to be sterilized in the apparatus different size inverters 7 and 17 are necessarily used, and as has been herein explained, it is also usually necessary to raise or lower the upper sections of the tanks 57 and 58.

In order to prevent any sideward motion of the cans -as they are being conveyed through the tanks 57 and 58, parallel, horizontal guide rails 55 are provided. A pair of the guide rails 55 is provided on each side of the path taken by the cans passing throughthe tanks (Fig. 2). These guide rails 55 run for substantially the entire length of the tanks and provide guidew-ays for the cans so that the cans will not move in a direction sideward to the direction of movement of the conveyor belt 13. The horizontal guide rails 55 are supported within the tanks 57 and 58 by vertical supports 75 (Fig. 2). These supports are suitably secured to the lower surface of the inwardly facing flanges 61 of the tanks 57 and 58 by screws 83. The guide rails 55 are secured as by welding to laterally extending horizontal braces 77, and these horizontal braces 77 in turn are slidably fitted into the vertical supports 75. It is, therefore, possible to move the pairs of horizontal guide r-ails together or apart so as to accommodate cans having various diameters. Once the horizontal spacing between the guide rails 55 is determined these positions may be maintained by tightening set screws 81 which secure the braces 77 in place in the vertical supports 75.

As the cans are being conveyed through tank 57 the inside of the cans is sprayed with a warm sterilizng solution, such as a solution of water and chlorine. This solution has strong sterilizng properties at temperatures below the boiling point of water. Temperatures below 200 F. are preferably used with this solution to sterilize the interior of cans having a lacquer coating. The spraying of the interior of the cans with the solution is accomplished by a longitudinally extending spraying member 85 which is suitably secured along the longitudinal axis of the tank 57 below the path of movement of the cans. The spraying member 85 includes a horizontal pipe 87 which is fitted with a plurality ofl spray nozzles 89 positioned along the upper surface of the pipe. These spray nozzles' 89 direct a suitable stream of sterilizng liquid upwardly into the interior of the cans as they are conveyed through the tank 57. t

The sterilizng solution is continuously pumped through the` sterilizng section 12 through a closed system, that is the sterilizng solution is recirculatedfofre.

f sterilizing section 12.

the tank through suitable piping 91 to a pump 93. The

`discharge of the pump 93 is connected by suitable piping 95 to the horizontal spray pipe S7. kIn this manner a substantially closed system is maintained in the sterilization zone 12, and, it is only necessary to supply fresh sterilizing liquid to this zone periodically as the supply of the sterilizing liquid within the zone diminishes, or as the concentraton of the chlorine in the water drops below a point where the sterilization activity is no longer sufcient. In order to prevent any foreign solid material which may be removed from the cans by the spraying action of the sterilzing liquid from entering the pump 93, a screen 97 is provided at the inlet end of the suction line 91. The pump 93 is drivingly connected to a motor 99 which supplies the pump 93 with the necessary power. A plug 98. is provided in the suction pipe 91 to permit the tank 57 to be drained when desired.

The sterilized cans usually have some sterilizing solution adhering thereto as .they leave the sterilization zone 12 and it is Lpreferable to wash off this so-lution. It is desirable to remove'this sterilizing liquid since sterilizving liquids usually have an antiseptic odor which is sometimes offensive, especially when the can is to be used for the packaging of food. The cans from the `sterilizing zone 1-2 are, therefore, directed through the opening 67 into the washing zone 15. The Washing zone 15 is provided by the tank 58 which is generally similar to the tank 57 provided in the sterilization zone. In the Washing zone 15 the cans which are conveyed through the washing tank 58 on the moving conveyor belt 13 are sprayed with water so as to remove any of the sterilizing liquid still adhering to the'cans.

The spraying of the interior of the cans with water is provided by a longitudinally extending spray member 102 which is mounted along the central axis of the tank 58 and includes a spray pipe 103 which is provided with a plurality of spray nozzles 105. The spray nozzles S are designed to direct a stream of water upwardly into the interior of the cans thereby washing out any of the `sterilizing liquid.

Fresh water is directed through a suitableinlet piping system into the horizontal spray pipe 103 and the Water is directed through the spray knozzles 105 upwardly into the interior of the cans. A drain 109 is provided in the bottom of the sterilizer to remove water therefrom. The water spray member 102V in the Washing section 15 is mounted tothe left of the center of thetank 58 so that the right `side of the tank S8 may be maintained as the draining section or draining zone 16. The water sprays are not directed into this draining zone 16 and, therefore, in this zone 16 substantially all of the water drains from the interior of the cans.

The conveyor belt 13 with the cans maintained on the lower run by the magnetic tiel-d created by the elongated magnet 11 continuously carries the cans through the washing section 15 vand draining section 16 and delivers Vthe cans through the exit opening 69 in the washing tank 58 to the second inverter 17.

The inverter 17, which is supported on the frame structure 21 at the outlet of the drying section 16, may be of conventional design and is illustrated as being generally similar to the inverter 7 at the inlet to the The roller 47 on the conveyor means 9 extends into the inverter so that the conveyor means 9 is holding the cans as they are delivered to the linverter 17. The inverter 17 vis of generally cylindrical outline with the axis of the cylinder horizontal. The inverter '17 is fabricated from a plurality of curved vguide rails 113. Some of these guide rails 113 extend to near the outlet opening 69 of the washing tank 58 and are positioned so that the cans are supported by these guide rails 113 before Athe cans are released from ,thejconveyor belt 13. The guide rails 113 guide the cans to turn through a4 180 angle as the .causare pushed through the inverter 17. The cans are thereby inverted and positioned with the open ends up.

The machine is provided with the take-olf conveyor 19 for receiving the upright sterilized cans-from.the inverter 17. The conveyor 19 is of conventional design and includes an endless conveyor belt 117 which is drivingly supported on a pulley 119. VPower is supplied to move the conveyor belt 117 by suitable power means (not shown).

Although shown and described with respect to particular apparatus and material, it will be apparent to those skilled in the art that vario'us modilicationsv might vbe made without departing from the principles of the disclosed invention.

l claim:

1. An apparatus for sterilizing metallic cans which comprises a tank having an elongated opening extending longitudinally along the top thereof and extending part way down the ends of said tank, va moving magnetic conveyor means extending along the top of said tank, said conveyor means being of such size and so positioned so as to close said elongated opening along the top of said tank and leaving open the extensions o'f said opening part way down the ends which provide inlet and outlet openings for said tank, means including a can linverter positioned adjacent one end of said passageway for delivering cans in inverted position adjacent the inlet opening in said tank, said conveyor means extending partially into said inverter so that said inverted cans are drawn against said magnetic co'nveyor means as the cans leave said inverter, a second inverter positioned adjacent the out-let end of said tank with said conveyor means extending partially into said second inverter, and spraying means within said tank for directing a stream of sterilizing liquid into the interior of said cans as said cans are conveyed through said tank by said conveyor means.

2. In apparatus fo'r sterilizing metallic cans, a tank having an elongated opening extending longitudinally along the top thereof and extending part way down the ends of said tank, a moving magnetic conveyor means extending along the top of said tank, said conveyor means being of such size and .so' positioned so as to close said elongated opening along the top of said tank andk -leaving open the extensions of said opening part Way down the ends whichprovide inlet and outlet openings for said tank through which cans may be conveyed by said conveyor means, said co'nveyor means including an endless ilexible moving conveyor belt. k

3. In apparatus fo'r sterilizing metallic cans, a tank having an elongated opening extending longitudinally along the top thereof and extending'part way down the ends of said tank, a moving magnetic conveyork means extending along the top of said tank, said conveyor means being of such size and sopositioned so as to close said elongated opening along the top of said tank and leaving open the 'extensions kot said opening part way down the ends which provide inlet and outlet openings for said. tank, said conveyor means including a moving flexible endless conveyor belt positioned so as to have 'an upper run and a lower rnnwith said lower run adacentsaid elongated opening along the top of said tank and a magnet po'sitioned adjacent the -top side of the lower run of ksaid moving conveyor belt of suicient strength to 'set up a magnetic iield to maintain a can in contact with and in Fixed relative position tothe' underside 'of the lower run of said moving conveyor belt, and means `for directing a canto said conveyor means so as to be contacted by the underside of lthe lower run of said moving conveyo'r belt.

4. In apparatus Vfo'r sterilizing metallic cans, a tank having an lelongated opening extending longitudinally along the top thereof and extending part way down the ends of said tank, a conveyor means on said tank including a moving flexible, non-magnetizable-endless 'conveyor belt and a magnet, said conveyor means being of such size and so positioned so' as to close said elongated opening along the top of said tank and leaving open the extensions of said opening part way down the ends which provide inlet and outlet openings for said tank, said moving conveyor belt being positioned so as to have an upper run and a lower run with said lower run adjacent said elongated opening along the top of said tank, said magnet being of sui'licient strength to set up a magnetic iield to maintain a can in iixed relative position to the underside of the lower run of said moiving conveyor belt, said magnet being positioned adjacent the top side of the lower run of said moving belt and across said elongated opening along the top o'f said tank, said magnet being spaced from said tank so as to provide a space for said conveyor belt, and means for directing a can to said conveyor means so as to be contacted by the underside o'f the lower run of said moving belt.

5. In apparatus for sterilizing metallic cans, a tank having an elongated opening extending longitudinally along the top thereof and extending part way down the ends of said tank, said tank having an upper section and a lower section with the upper section fitted in telescoping relationship with the associated lower section, means for vertically moving said upper section to adjust the relative lamount of telescoping between said sections, a conveyor means on said tank including a moving flexible, non-magnetizable endless conveyor belt and a magnet, said conveyor means being of such size and so positioned so as to close said elongated opening along the top of said tank and leaving open the extensions of said opening part way down the ends which provide inlet and outlet openings for said tank, said moving conveyor belt being positioned so as to have an upper run and a lower run with said lower run adjacent said elongated opening along the top of said tank, said magnet being of suicient strength to set up a magnetic iield to maintain a can in llixed relative position to the underside of the lower run of said moving conveyor belt, said magnet being positioned adjacent the top side of the lower run or" said moving belt and across said elongated opening along the top of said tank, said magnet being spaced from said tank so as to provide a space for said conveyor belt, and means for directing a can to said conveyor means so as to be contacted by the underside of the lower run of said moving belt.

6. An apparatus for sterilizing metallic cans which comprises a first tank and a second tank, said tanks having an elongated opening extending longitudinally along the tops thereof and extending part way down the ends of said tanks for at least a distance equal to the axial dimension of a can to be sterilized in said apparatus, said opening having a transverse dimension at least equal to the diameter of a can to be sterilized, a moving magnetic conveyor means extending along the tops of said tanks, said conveyor means being of such size and positioned to close said elongated opening along the -tops of said tanks and leaving open the extensions of said opening down the ends which provide inlet and outlet openings for said tanks, said conveyor means including a moving flexible, nonmagnetizable endless conveyor belt positioned so as to have an upper run and a lower run with said lower run adjacent and parallel to said elongated opening along the top of said tanks, a magnet positioned adjacent the top side of the lower run of said moving belt, said magnet being of suicient strength to set up a magnetic ield to maintain said cans in xed relative position to the underside of the lower run of said belt, guide rails within said tanks extending parallel to the direction of travel of said conveyor belt, at least one guide rail positioned on each side of the path of said cans through said tanks, said guide rails being positioned to prevent motion of said cans transverse to the direction of movement of said conveyor belt, a first spray means within said iirst tank positioned to direct a stream of sterilizing liquid into said cans and a second spray means within said second 'tank positioned to direct a stream of water into said cans after they have been sprayed with said sterilizing liquid.

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